Television system



March 24, 1931. T. A. SMITH TELEVISION SYSTEM Filed July 19.

rum/rim F a W w W INVENTOR T A. SYVHT BY 7 ATTORNEY Patented Mar. 24, 1931 UNITED STATES PATENT OFFICE THEDDORE A. SUITE, BIDGEWOOD, NEW JERSEY, ASSIGNOR TO RADIO CORPORA- T1018 OF AMERICA, A CORPORATION OF DELAWARE TELEVISION SYSTEM Application filed July 19,

The present invention relates to television systems, and, in particular, to television systems adapted for use in connection with the television transmission of motion picture films and the like.

In connection with motion picture films, it is well recognized in the art that the standard film which is provided for projection in motion picture houses is usually formed from 1 a series of distinct frames which are separated from each other by a definite frame line, and in case of television transmission of such types of subjects where the usual spiral or mirror disk 18 used, it is noticed that objectionable effects are produced at the receiver in that the frame line must always be reproduced during each step by stepmotion of the film with respect to the analyzing system, assuming, of course, that a spiral disk scanning system is used. Also, if a scanning disk in which the apertures or lenses therein are arranged in a circle and the motion picture film is continuously fed forward with respect to the scanning element so as to produce the relative motion therebetween, as in the case of continuous feed transmission systems, the frame line is likewise found to exist in the received icture.

There ore,-a s a principal object of my invention, I have sought to provide a method and means by which the objection able effects of transmission of the frame lines and the like on motion picture films may be avoided.

Other objects of my invention are to provide a novel scanning element for accomplishing the elimination of the frame line be tween successive frames of motion picture films for television transmission so that only the picture area of the transmitted subject 0 matter is analyzed.

Still other objects of my invention are to provide a scanning element for use in connection with television systems adapted to transmit motion picture films which is readily adaptable to the present known types of 1928. Serial No. 879,385.

existing apparatus utilizing, for example, the continuous feed type of motion picture film apparatus, without the need of transmitting the frame line, or even the outermost portion of the film including the edge portion having the drive sprocket holes, or the sound track portion adjacent the picture.

Other objects of my invention are to provide a scanning element for television systems adapted to,transmit motion picture films, and the like, which is relatively simple in its construction and arrangement, one which is easy to manufacture, convenient to install, and hi hly efficient in its use.

Still other 0 jects and advantages of my invention will hereinafter appear from a consideration of the following specification and claims in connection with the accompanying drawing, wherein:

Fig. 1 illustrates in a schematic manner a system utilizing the s ecialized type of scanning element which Fhave developed; and,

Fig. 2 illustrates, in an enlarged detail, further embodiments of the scanning element.

Now referring to the drawings, I have shown a motion picture film 1 adapted to be wound upon a pair of reels 3, and a motor 5 provided with a shaft or spindle 7 ada ted to drive through an appropriate gear re uction system 10 a pair of sprocket wheels 9. The sprocket wheels 9 are arranged to rotate in the sprocket holes 11 provided on the outside edges of the motion picture film 1, and where a constant speed or synchronous motor is provided and where the motion is pro erly synchronized so as to rotate at a uni orm rate, the motion picture film may thus be continuously fed forward at a substantially constant speed.

Removed from the motion picture film 1 and behind the same, I have provided a light source 13 which may be either of the incandescent or are ty e, or any other desirable type, and arrange to project the light beams circular path, because the pitch of the spiral is very slight and is only an amount equal to the width of the frame line between successive picture frames or elements forming the entire motion picture film as is more par ticularly shown by Fig. 2 of my drawings. Thus, if it is assumed that the disk element 17 is rotating before the lens system 15 associated with the light source 13 in a counter clockwise direction, as shown. the first element of the scanning disk will trace a path 29 across the motion picture film as designated by the arrow on the film. and the next hole in the disk will trace a path corresponding to the same path traced by the previous ions or aperture projecting the light from the source, with the exception that the motion picture film has been advanced during the transverse movement of the light spot produced by the light passing through the aperture or lens in the scanning disk an amount equal to the width of one line of the picture so that the second line traced on the motion film by the light source will approxi matel Y correspond in position to the first line. but, with regard to the film, will be moved upwardly thereon a predetermined amount.

Now. if it is considered that all of the apertures or lenses in the scanning disk as far as the last lens or aperture thereon in the spiral pass before the lens system 21 so as to project the light from the source as a point on the film. it will be noted that when light passes through the last aperture or lens 0 of the ries of apertures or lenses. in the scanning disk that the path traced on the disk will correspond to a point just beneath the frame line thereon. and that if the holes in the disk were arranged along a circular path that the next line on the film which would be traced would be the frame line. but since the pitch of the spiral is equal to the width of the frame line, after the entire frame of the film has been transmitted and the picture effectively jumps the frame line. it will be seen that the process of scanning the motion picture film frame will be repeated. with the omission of any scanning period as regards the frame lines and the like.

For the purpose of projecting the light issuing through the apertures or lenses in the disk. I have provided a lens 21 so as to focus the light from the disk as a point source upon the film. and directly behind the film. I have provided a photoelectric cell or member 23 which electrically responds by an amount proportional to the varying intensities of light and shadow on the film so as to produce modulation of a transmitter in accordance with the current flow through the cell, and thus vary the same directly in accordance with the intensity of light and shadow on the film itself.

The photo cell may be connected through an appropriate form of amplifier and arranged to have its output modulate a radio or wire transmitter. or the like, so that energy ma be transmitted to a distinct point, at which it may be received and properly amplified and arranged to actuate a glow lamp, or the like, which will produce light intensities at the receiving point corresponding and proportionate in value to the intensities of light and shadow on the transmitted motion picture film.

As I have shown in the accompanying drawing. in order to provide an arrangement such that the picture portion only of the film may be scanned, I have provided a mask 28 inserted between the lens 21 and the film 1. This mask is of particular use in cases where the film 1 is accompanied by a sound record 30 placed directly thereon and the mask ma be of any appropriate rectangular size pre crably to correspond with the individual frames of the picture such that the light beam focused upon the film through the lens 21 and caused to trace a path transverse thereto will also strike such portions of the film as carry picture representations. Also, where desired, instead of placing the mask between the lens 21 and the film 1. it is also fully within the scope of my invention to place the mask before the photo cell condenser lens so as to screen the cell from all portions of the film other than the individual picture frames. The aperture of this mask need only be slightly higher than the width of a beam of light from a single scanning aperture but should be of such a width that the scanning spot cannot impinge upon the sound track at one side of the film nor beyond the edge of the picture frame at the other side.

Also. as has been suggested in my copending application. Serial No. 379.384, filed July 19. 1929. where it is desired to transmit motion picture film having the sound accompaniment directly thereon as is indicated by the sound track 30. I inay provide a suitable sound head arrangement for converting the sound impressions placed upon the record into electrical impulses. as has been shown in the above named copending application. In such a case. where desired. I may also transmit the sound accompaniment directly with the transmission of the picture through appropriate means fully disclosed in the said copending application.

By Fig. 2. I have more particularly illus t'ratcd my scanning disk. By Fig. 2. I have shown several of the apertures or lenses extending about the disk wherein a designates letter glow lamp,

the first of the series and c the last of the series. The path b indicates a path corresponding to a circular spacing and positioning of the apertures and the amount of spiral pitch which I actually impart in the 360 to the lenses or apertures is indicated by the height of the spiral which is shown by the d. The width (I as diagrammatically shown is intended to indicate the width of a frame line or distance between two component frame lines 25 on the motion picture film 1.

In order to receive pictures or visual rc productions of films transmitted by the arrangement herein set forth, I provide at the receiver, a corresponding scanning disk arranged to cooperate with the light producing element so as to rebuild the transmitted picture on a screen, or the like. However, at the receiving point, the disk may differ from the type at the transmitter, since the transmitter obtains a relative motion between the scanning disk and the scanned object or film by virtue of the fact that the film is continuously moved with respect to the scanning element having all apertures or lenses thereof along a path which is a very slight spiral and will substantially correspond to a circular path, but since at the receiver there is no means for imparting any relative motion between the source for rebuilding the light for illumination of a screen and the screen it self, I prefer to provide the usual type of Nipkow spiral disk for cooperation with a which may be either of the plate or point discharge type so that the received picture may be built up in the usual manner in a line for line manner in which the successive lines thereof are reproduced any predetermined and suitable number of times per second, of which number, 16 to 20, or 24, repetitions per second has been found to be satisfactory.

Other changes and modifications such as may readily suggest themselves to those skilled in the art will, of course, be the mirror disk having the successive mirrors thereon arranged in a path corresponding substantially to the arrangement of the successive apertures or lenses in the rotating scanning disk and arranged to cooperate with a con tinuously moving motion picture film projecting in any appropriate manner with respect to this type of scanning system, or, where desired, I may provide a fixed bank of mirrors and a smaller rotary scanning element of the mirror type or disk type for c0- operating therewith, or I may provide a drum type scanning element with an internally arranged light source, without departing from the spirit and scope of my present invention.

Other changes and modifications will at once suggest themselves and become apparent to those skilled in the art to which the invention relates, and, therefore, I desire to have my invention broadly construed and believe myself to be entitled to make any and all modifications of my invention such as fall fairly within the spirit and scope as defined by the hereinafter appended claims, wherein I claim 1. In a television system for transmitting motion picture film, means for continuously moving the film subject to be transmitted at a uniform rate of speed, and means for analyzing the picture portion only of the film.

2. In a television system for transmitting motion picture film, means for continuously moving the film subject to be transmitted at a uniform rate of speed, and means for analyzing the subject in such manner that the frame lines separating successive portions of the said film are omitted.

3. In a system for transmitting motion picture films having successive pictures thereon separated by a frame line on the film, means for moving the film subject to,be transmitted at a constant and uniform rate of speed past a predetermined point, means for analyzing the varying intensities of light and shadow on the film subject and converting the said varying intensities of light and shadow into electrical variations, and means providing for the omission of the frame lines separating the successive pictures on the film from the analyzing process.

4. In a system for transmitting motion picture films having successive pictures thereon separated by a frame line on the film, means for moving the film subject to be transmitted at a constant and uniform rate of speed past a predetermined point, means for scanning said film in a line for line manner along a path traverse to the path of motion thereof. and means provided on said scanning means for interrupting the sequence of sai lines of scanning to eliminate the frame lines separating the successive pictures on the film from the scanning path.

5. In a television system for transmitting motion picture films, a scanning device having a plurality of scanning elements arranged thereon, means for continuously moving the film relative to said scanning element at a uniform rate of speed, means provided by said scanning device for analyzing the film in a line for line manner during the relative motion of said film with respect thereto, and means provided by the scanning device for analyzing only the picture portion of said film record.

6. In a system for transmittin motion picture films by television, means or moving a motion picture film subject at a uniform constant rate of speed relative to a predetermined point, a scanning element, means provided by said scanning element for analyzing the intensity of light and shadow on said film subject, means for convertin the va ing intensities of light and she ow on t e t film subject into electrical energy variations, and means also provided by said scanning element for scanning the picture portion only of said motion picture film subject.

In a television system for transmitting motion picture films, a scanning device having a plurality of scanning elements arranged thereon. means for continuously moving a film subject to be transmitted relative to said scanning device at a uniform rate of speed, means provided by said scanning device for analyzing the film in a line for line sequence during the relative motion of said film with respect thereto, and means also provided by the scannin device for interrupting the sequence of said lines of scanning, whereby the scanning path passes over each frame line and scans the picture portion only of said film record.

8. In a system for transmitting motion picture films by television, a scanning device, means for moving a motion picture film subject at a uniform constant rate of speed relative to said scanning device, means provided by said scanning device for analyzing said film subject in a sequential line for line manner, means for converting the varying intensitics of light and shadow on the film sub ject as determined by said line for line analyzing into electrical energy variations, and means also provided by said scannin element for interrupting the sequence 0 said iines of scanning as each complete picture frame is scanned so as to pass over the frame line separating successive pictures of the film and scan the picture portion only thereof.

9. In a television system for transmitting motion picture films, a rotary scanning element having a plurality of scanning elements arranged thereon in a spiral path having a pitch equal to the width of t e frame line separating successive pictures on motion picture film to be transmitted, means for longitudinally advancing said picture film at a constant and uniform rate relative to said scanning element, means provided by said scanning element for scanning the film in a line for line manner during the relative.m0 tion of said film with respect thereto, and means provided by the scanning element for interrupting the sequence of said lines of scanning at periods when the frame lines on said film would normally follow the scanning in line for line sequence, whereby the picture portion only of said film record is scanned.

10. A scanning device for use in the television transmission of motion picture films comprising a rotatable member having a plurality of scanning elements arranged thereon in such manner as to scan the picture portion only of the said motion picture film.

11. A scanning device for use in connection with the television transmission of mothereon in a spiral g; the width of the frame line on the said 12. A scanning device for use in the television transmission of motion picture films having the successive picture frames separated by a framing line which includes a disk member elements arranged about the surface thereo in a spiral path having a pitch e ual to the width of the frame line on the sai film.

13. In a television system for transmitting motion picture films, a scanning device having a plurality of scanning elements furcontinuously moving the film relative to said scanning device at a uniform rate of speed, means provided by said scanning device for analyzing the film in a line for line manner during the relative motion of said film with respect thereto, a photoelectric element for convertin variations in intensity of light and she ow on the scanning action into varying electrical currents, and a mask interposed between said scanning device and said photoelectric element for limiting the response of said hotoelectric element to the variations in lig t and shadow on the picture frame portion only of said film.

14. The method 0 analyzing motion pictransmission which consists in continuously and uniformly advancing the film relative to a predetermined point, and in analyzing the lm in such manner as to analyze the picture portion only thereof.

15. The method of transmitting motion picture films having the successive frames thereon separated by frame lines which consists 1n continuously and uniforml ties of light and shadow on the successive picture frames in such manner that the frame lines separating successive picture frames are omitted from the analyzing process.

16. The method of electrically transmitting motion picture film having the successive picture frames thereof separated by a ting motion picture film having the successive picture frames thereof separated by a frame line which consists in continuously and uniforml moving the film relative to a 3 predetermin' e point, 1n analyzing the vagmg intensities of light and she ow on e film frames, in converting the va g intensities of light and shadow on the surface I into varying electrical energy pulses, in omitting from the analyzing process the frame lines separating successive picture frames of the film, and m limiting the conversion of varying intensities of light and shadow on the film into electrical energy pulses to picture portions only of the film.

THEODORE A. SMITH.

' and uniformlg ting motion picture film having the successive picture ames thereof separated by a frame line which consists in continuously moving the film relative to a predetermine point, in analyzing the va mg intensities of light and she ow on e film frames, in converting the va ng intencities of light and shadow on the 111 surface into varying electrical energy pulses, in omitting from the analyzing process the frame lines separating successive picture frames of the film, and in limiting the conversion of varying intensities of light and shadow on the film into electrical energy pulses to picture portions only of the film.

THEODORE A. SMITH.

DISCLAIMER 1,797,378.fl'he-d0re A. Smith,

dated March 24, 1931.

following words, to wit:

A scanning devlce thereon in such manner as film-7| [Oflicial Gazette January 31, 1933.]

Ridgewood, N. J. TELEVISION Srsrnu. Patent Disclaimer filed January 3, 1933, by the patentee, assignee, Radio Corporation of America, assenting. Hereby enters this disclaimer to claim 10 in the said specification which is in the for use in the television transmission of motion picture films comprising a rotatable member having a plurality of scanning elements arranged to scan the picture portion only of the said motion picture DISOLAI MER l,797,378.Tlw dore A. Smith, Ridgewood, N. J. TELEVISION SYSTEM. Patent dated March 24, 1931. Disclaimer filed January 3, 1933, by the patentee, assignee, Radio Corporation of America, assenting. Hereby enters this disclaimer to claim 10 in the said specification which is in the following words, to wit:

A scanning device for use in the television transmission of motion picture films comprising a rotatable member having a plurality of scanning elements arranged thereon in such manner as to scan the picture portion only of the said motion picture 

